The U.N. Security Council will meet on Thursday to formulate its response to North Korea’s launch of ballistic missiles which breached its resolutions and prompted international criticism, Seoul officials said.

The closed-door meeting is scheduled for 4:30 p.m., Eastern time, between the representatives of 15 member countries of the council. It came at the request of the United States.

North Korea fired two midrange ballistic missiles into the East Sea Wednesday in an apparent show of force against ongoing annual South Korea-U.S. military exercises. Its first launch of the Rodong missiles in four years followed a string of short-range rocket liftoffs over the past two months.

Seoul and Washington condemned Pyongyang for violating Security Council resolutions that bar its use of ballistic missile technology, while Beijing expressed concerns about escalated tension in the region.

In this July, 2013 photo, military trucks carry Rodong missiles during a military parade at Kim Il Sung Square in Pyongyang, North Korea. North Korea on Wednesday, (Yonhap)

The launches coincided with a trilateral summit of the leaders of South Korea, the U.S. and Japan during which they reaffirmed their commitment to denuclearize the communist state.

Ri Tong-il, deputy representative at the North Korean mission at the U.N., berated the U.S. at the agency’s headquarters on Monday for exacerbating tension through the joint military drills, threatening to take “additional measures to show off its nuclear deterrent.”

U.N. Secretary-General Ban Ki-moon issued a statement criticizing the launches, which he said were “contrary to building trust in the region.”

“The secretary-general urges the DPRK (North Korea) to cease its ballistic missile activities and focus, together with other countries concerned, on the dialogue and diplomacy necessary to maintain regional peace and security,” the statement said.

At the special session, the council members will work to devise “appropriate measures,” diplomats say. South Korea and the U.S. may propose a resolution or presidential statement, as China would likely oppose further sanctions or other strong punishment.

“We will make efforts to come up with a response at the Security Council in close consultation with other members,” Foreign Ministry spokesman Cho Tai-young told reporters.

Marie Harf, deputy spokesperson of the U.S. Department of State, said Washington is discussing the situation with its partners on the council and other regional allies to “determine what the best way is to move forward.”

“This is a troubling and provocative escalation that we’ve seen over the past several weeks. We take it very seriously,” she told a press briefing.